Antitussive, Expectorant and Antipyretic Effect of the Ethanolic Extract of the Leaves of Momordica charantia L.

The traditional use of the M. charantia L. plant to treat coughs, fever and expectoration is widely practiced in different cultures, but its effectiveness and safety still require scientific investigation. This study sought to perform a chemical analysis and evaluate the antitussive, expectorant and antipyretic effects of the ethanolic extract of M. charantia leaves (EEMc) in rats and mice. The EEMc was subjected to chemical analysis by HPLC-DAD, revealing the presence of the flavonoids astragalin and isoquercetin. Acute oral toxicity in mice did not result in deaths, although changes in liver weight and stool consistency were observed. EEMc demonstrated an antitussive effect at doses of 100 and 300 mg/kg in mice subjected to cough induction by citric acid nebulization. Furthermore, it showed expectorant activity at a dose of 300 mg/kg, assessed based on the elimination of the phenol red marker in bronchoalveolar lavage. In the evaluation of antipyretic activity in rats, fever induced by Saccharomyces cerevisiae was reduced at all doses tested during the first hour after treatment. This innovative study identified the presence of astragalin and isoquercetin in EEMc and indicated that the extract has antitussive, expectorant and antipyretic properties. Therefore, EEMc presents itself as a promising option in herbal medicine for the treatment of respiratory symptoms and fever.

Antitussive, antispasmodic, bronchodilating and cardiac inotropic effects of the essential oil from Blepharocalyx salicifolius leaves.

ETHNOPHARMACOLOGY RELEVANCE: Blepharocalyx salicifolius (Kunth) O. Berg (Myrtaceae) is a tree native to Argentina and Uruguay that grows and is cultivated along the riverside of the Rio de la Plata. The leaves of this plant species, locally known as "anacahuita" are used in South America to prepare infusions for the empiric treatment of cough and bronchospasm, as well as diarrhoea and other intestinal disorders. Although previous phytochemical studies have been performed with the essential oil extracted from Blepharocalyx salicifolius, pharmacological evidence supporting its traditional use is still lacking. AIM OF THE STUDY: To experimentally evaluate the pharmacological properties of Blepharocalyx salicifolius based on its traditional use. The studies were performed with tincture (T-Bs) and essential oil (EO-Bs) prepared from its leaves, in isolated rat trachea, intestine and heart preparations. METHODS: The ex-vivo effects of T-Bs and EO-Bs were evaluated with the agonists carbachol (CCh) and calcium chloride (Ca2+) in the contractile concentration-response curves (CRC) of the isolated intestine. The muscle relaxant effect of EO-Bs was evaluated in the isolated trachea and compared with the effect achieved with papaverine as a positive control. The T-Bs and EO-Bs cardiac effects were analysed by perfusion of an isolated rat heart before a period of ischemia/reperfusion (stunning model). The antitussive effect of both T-Bs and EO-Bs was evaluated in mice exposed to ammonia using codeine as a positive control. RESULTS: Both T-Bs and EO-Bs induced a non-competitive inhibition of the CCh-CRC in the rat intestine, with IC50 values of 170.3 ± 48.5µg T-Bs/mL (n = 6) and 5.9 ± 1.6µg EO-Bs/mL (n = 6), respectively. EO-Bs also inhibited non-competitively the Ca2+-CRC, with IC50 value of 1.8 ± 0.3µg EO-Bs/mL (n = 8). A similar effect was obtained with the main active component of the EO-Bs 1,8-cineole. In isolated trachea, EO-Bs induced the relaxation of the CCh-contracted tissue (1.7 ± 0.2µg EO-Bs/mL, n = 11) up to a maximal relaxation that was 1.9 times higher than that of papaverine. In the isolated heart, EO-Bs induced a poor negative inotropic response, and did not improve the contractile and energetic recovery after ischemia and reperfusion. In the mouse cough model, EO-Bs (90mg/Kg) was as effective as codeine (30mg/Kg) in reducing cough frequency. CONCLUSIONS: The results indicate that the preparations from Blepharocalyx salicifolius leaves were effective as central antitussive, bronchodilating and antispasmodic agents, suggestive of a mechanism associated with the inhibition of Ca2+ influx into smooth muscle. The EO-Bs displayed only a poor ability to reduce cardiac inotropism, and was devoid of any cardioprotective properties. Thus, the present study validates the traditional use of this South American plant for asthma, cough and bronchospasm, shedding new light into its potency and putative mechanism of action.

Evaluation of anti-tussive activity of Chamaedorea tepejilote.

AIM OF THE STUDY: Evaluate the potential inhibition of cough in a mouse model induced by sulfur dioxide gas of methanol and chloroform extracts of aerial parts of Chamaedorea tepejilote. MATERIAL AND METHODS: The antitussive effect was examined using the Ogyhara method. The extracts and theobromine were orally administered to mice. Each extract was administered to one group (400mg/Kg) and theobromine (2mg), and negative control received PVP. The frequency of cough was measured at 60, 90min after the administration of chloroform extract. RESULTS: The water extract of C. tepejilote had no effect on the pharmacological model used in this study. The effects of the methanol and chloroform extracts of this plant on sulfur-dioxide-induced cough in experimental animals show activity dose-dependently in the range between 100 to 500mg/Kg. At doses of 400mg/kg, the methanol and chloroform extracts inhibited cough by 41.72% and 49.1%, respectively; these results are comparable to the effect produced by the antitussive agent theobromine (53.4% inhibition). CONCLUSIONS: Both extracts exhibited significant antitussive activity, and the effect of the chloroform extract was dose dependent. The antitussive activity of this extract was comparable to that of theobromine. The effect of chloroform extract on the trachea was also tested; it did not relax pre-contractions in guinea pig trachealis induced KCl, carbachol or histamine.

Studies on bioactive components from Chinese medicinal plants.

Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well as novel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, China. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as 1H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, structure elucidations and bioassay results will be reported.

Studies on bioactive components from Chinese medicinal plants

Several novel bioactive components isolated from Chinese medicinal plants will be presented. These include novel maytansinoid tumor, inhibitors, some new ent-kaurane and rosane diterpenoids from Mallotus anomalus Meer et Chun (Euphorbiaceae), as well asnovel insecticide, stemona alkaloids from Stemona parviflora C. H. Wright (Stemonaceae). Both are native plants of Hainan island, Chine. 2D NMR techniques such as mono and hetero-COSY, NOESY, COLOC as well as H-NMR line broadening effect were utilized for structure elucidation. The separation techniques, struture elucidations and bioassay results will be reported.